I have received my TPG SIMCARD, but before I activate it, I just want to confirm that my current SIMCARD will continue to be operational while the number is being ported to you, TPG.
You can start the porting process. When your current service becomes unavailable (SOS signal), you can switch to your new SIM card. It usually does not take a long time to port. Should be done within an hour. I have done several ports to other providers and they usually tell you it might take like 1-2 days.